The present invention relates to a method of removing hydrosulfide from partial oxidation gas. More particularly, it relates to a method of removing hydrosulfide from a crude gas produced by partial oxidation (gasification) of carbon containing material, and particularly such a method in which the gas is treated at a temperature between 10.degree. and 60.degree. C. with an absorption solution suitable for this purpose and then subsequently the loaded absorption solution is regenerated by heating.
Methods of the above mentioned general type are known in the art. It is known to remove hydrosulfide from a so-called partial oxidation crude gas or other gases by treating the gases with an absorption solution suitable for this purpose. The gas is supplied with a temperature between 10.degree. and 60.degree. C. from above into an absorption column provided with respective inserts, and the absorption solution is fed to the head, so that it flows in counterstream to the gas from above downwardly through the absorption column. The utilized absorption solutions can contain various compounds as effective substances. Especially suitable for the above purpose are for example various amines, glycoles and also N-methylpyrrolidon and propylenecarbonate. The hydrosulfide of the gas is physically dissolved during the washing process in the absorption column in the utilized absorption solution or chemically bonded with the latter. Subsequently, the loaded absorption solution is supplied to a desorption column. In the desorption column the hydrosulfide is driven from the solution by heating at a normal pressure or at reduced pressure. After this, the regenerated solution is supplied to its further utilization.
When these steps were used for treating the partial oxidation crude gas, it was conventional to cool and to purify the crude gas between the gasifier and the absorption column in a series of process steps, so that this gas can be subsequently supplied to the absorption column with a temperature between 10 and 60.degree. C. For example in the magazine "gwf-gas/erdgas", 121 (1980), volume 12, page 545, FIG. 3, a flow diagram for such a gas treatment is presented. Here the crude partial oxidation gas is first cooled in the heating boiler of the gasifier and then supplied through a so-called cooling washer to a mechanical washer and an electrical filter. Then, the cooled and pre-cleaned gas is supplied to the absorption column. In such a process it is however required that heating of the desorption column, in which the regeneration of the loaded absorption solution is performed, be conducted with foreign vapor. It is to be clear that this involves an additional cost factor for the method, which should be eliminated if possible.